


Having a Bath Time

by Shadowinflame



Series: Things Inspired by Twitter [4]
Category: Undertale (Video Game)
Genre: Asphyxiation, Bath Sex, Bathtub Sex, Breathplay, Double Penetration, Dreamtale Nightmare Sans (Undertale), Ecto-Body (Undertale), Ecto-Breasts (Undertale), Ecto-Genitalia (Undertale), Ecto-Vagina (Undertale), Ectobiology, Kinda, Nipple Play, Other, Tentacles, i guess
Language: English
Status: Completed
Published: 2020-10-23
Updated: 2020-10-23
Packaged: 2021-03-08 23:41:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,106
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27164687
Author URL: https://archiveofourown.org/users/Shadowinflame/pseuds/Shadowinflame
Summary: Nightmare's tentacles have a mind of their own headcanon, featurig Nightmare who just wants to enjoy a nice bath after some hard work
Series: Things Inspired by Twitter [4]
Series URL: https://archiveofourown.org/series/1963651
Comments: 8
Kudos: 101





	Having a Bath Time

**Author's Note:**

> Inspired by [this Twitter post](https://twitter.com/ExistsAnxiously/status/1317731505079242752)  
> Art is just so fricking inspiring, I can't help it.

Nightmare sighed, sinking into the warm water of the bathtub. He sent everyone out on missions to have some quality time all on his own in a completely empty castle for once and what better way to spent it than to take a long, well deserved bath. He leaned his head back and let the warmth wash over his aching bones.

At first he barely even noticed his tentacles acting on their own as he had his eyes closed and the was they caressed his bones felt soothing. But as they went down in between his legs, starting to spread them apart and rub at his pelvis Nightmare's eyes snapped open and he pressed his legs together.

“What the hell!”, he shouted. “What do you think your doiiiinnngg! F-fuuck!”

His tentacles knew exactly how to get him, one of them just slightly dipped into his pelvis and his ecto formed around it within seconds. Oh, how he hated it.

“S-stupid tentacles”, he mumbled as one started rubbing between his folds, stimulating his clit in the process. “C-come on, just let me enjoy a bath for once”, he almost whined, grabbing the tentacle and removing it from his pussy. It writhed in his hand and he stared at it angrily. Not for long though, as another one already poked at his entrance moments later.

“That's not funny!”, Nightmare complained, reaching down with his second hand to remove that tentacle as well.

He really hated that he had more tentacles than he had hands as a third one started rubbing his clit. He moaned reluctantly, phalanges pressing into the two tentacles he was holding. This was horrible.

Nightmare gasped in shock as his last tentacle pressed down on his wrist, forcing him to let go of the tentacle he held in that hand. The now free tentacle resumed the action on his other hand and shortly after he found his wrists held together over his head by his own tentacle. They really didn't want him to interfere it seemed.

With his hands bound there was nothing he could do as a tentacles wrapped around each of his legs, spreading them apart and pinning them on the rim of the bathtub. The tentacle down at his pussy had free access now and it was so ready to make good use of it.

Despite all his complaints, Nightmare was dripping wet, not only from the water of the bathtub and the tentacle had no problem at all as is slithered inside of him.

Nightmare pressed his teeth together, no way he was gonna moan, even if no one was there to hear him! But the way the tentacle thrust in and out of him, filling him so perfectly had his legs trembling. He hated that it made him feel so good, hated that his tentacles always found the right moment to tear down his walls and show him his basic needs.

 _What a mess_ , he thought.

One tentacle let go of his leg but Nightmare didn't even attempt to pull it off from the rim of the tub. The tentacle continued to move up to his large breasts that he formed along with his pussy, wrapping around one of them and squeezing down on it roughly.

Nightmare couldn't help the moan that escaped him at that, hips rocking down onto the tentacle inside of him. Maybe he should finally admit he enjoyed this instead of struggling against it, but he still had a glimmer of dignity to hold onto.

Which almost got lost as the tentacle thinned out to wrap around his nipple, teasing the sensitive bundle of nerves with a tip that seemed almost small enough to fit inside.

“S-shit”, Nightmare cried out, hands fighting against the tentacle that restrained them. He wouldn't cum from this!  
Suddenly, Nightmare was glad he was alone in the castle as he felt the tentacle inside him thrust deep into his stomach, curling and uncurling against the walls of it. He screamed and moaned, hips trying to somehow fall into a rhythm with his appendage, forcing it deeper inside. He struggled to get his hands free once more, longing for some kind of friction on his clit.

He screamed out again as a tentacle wrapped around his stomach, squeezing down on it and making him so painfully aware of the tentacle inside of him. He was shocked as the tentacle seemed to just lift him, turning him around so that he was on his knees, hands still bound and now resting on the rim of the bathtub. Then the tentacle moved down to his pussy as well and started pressing into it.

Nightmare was about to cry, it just felt way too good. He had been longing for sex for some time now, but he was too tense and always told himself he had too many other things to do anyway and... no way he was gonna let even one of his subordinates see him like this.

The tentacle finally slipped inside of him and Nightmare let out a loud moan, throwing his head back. Filled to the brim like this, he was getting close.

He didn't notice the other tentacle leave his breasts, but he was made aware of it as he suddenly sensed it on his head. He didn't get any time to question what it was doing there before his head got pressed into the water below him. His mouth reflectively opened as all the air got fucked out of his body by his the tentacles inside of him and he felt the water flow into him. 

He gasped and coughed up water as soon as the tentacle pulled him up again, tears and water flowing down his face alike. “F-fuck”, he breathed.

The tentacle gave his head a little shove to prepare him this time, before shoving his head back into the water and Nightmare drowned in the feeling of the air slowly leaving him this time. Both tentacles inside of him thrust into him at an agonizing pace now and he felt his walls tighten around them.

The tentacle around his wrists finally let go and moved down to his clit, rubbing over it just a little. Nightmare came right then and there, the combined stimulation too much to handle in his already oxygen-deprived state. His tentacles pulled him up again and he rested his head in his arms on the rim of the tub as his tentacles still worked him through his orgasm before pulling out. 

“S-stupid fucking tentacles”, Nightmare moaned, still gasping for air. That was not what he imagined his 'relaxing bath' to be like.

**Author's Note:**

> Hahahaha


End file.
